Welcome! I always advise not to actively try to lose weight for the first six weeks or so, so your supply gets well-established.
Just try to make good food choices. Me personally, I'm doing Sugar Busters, which is what helped me lose 30 pounds between the first two pregnancies (not doing it helped me lose only 10 pounds between the next two, so I've learned my lesson!). It's all about finding a plan you can live with & making sure you get enough to eat and drink.